Problem: Recently, Anton has found a set. The set consists of small English letters. Anton carefully wrote out all the letters from the set in one line, separated by a comma. He also added an opening curved bracket at the beginning of the line and a closing curved bracket at the end of the line. 

Unfortunately, from time to time Anton would forget writing some letter and write it again. He asks you to count the total number of distinct letters in his set.

Input

The first and the single line contains the set of letters. The length of the line doesn't exceed 1000. It is guaranteed that the line starts from an opening curved bracket and ends with a closing curved bracket. Between them, small English letters are listed, separated by a comma. Each comma is followed by a space.

Output

Print a single number — the number of distinct letters in Anton's set.

Examples

Input

{a, b, c}


Output

3


Input

{b, a, b, a}


Output

2


Input

{}


Output

0

Solution (in JAVA):

Solution:
import java.io.*;
import java.util.*;

/**
 * Created by bassel on 2/13/16.
 */

public class ACM {
    public static void main(String[] args) throws Exception {
        IO io = new IO(System.in, System.out);
        io.solve();
    }

    private final static class IO {
        public void solve() throws Exception {
            Set<Character> s = new TreeSet<Character>();
            Scanner input = new Scanner(System.in);
            while(input.hasNext()) {
                String alpha = input.next().replaceAll("[{},]", "");
                if(alpha.length() > 0)
                    s.add(alpha.charAt(0));
            }
            print(s.size());
            flush();
        }

        private static IO lol;
        private static BufferedReader in;
        private static PrintWriter out;
        private static StringTokenizer tokens;

        private IO(InputStream in, OutputStream out) {
            this.in = new BufferedReader(new InputStreamReader(in));
            this.out = new PrintWriter(new BufferedOutputStream((out)));
        }

        private static final String next() throws Exception {
            if(tokens == null || !tokens.hasMoreTokens())
                tokens = new StringTokenizer(in.readLine());

            return tokens.nextToken();
        }

        private static final String nextLine() throws Exception {
            return in.readLine();
        }

        private static final int nextInt() throws Exception {
            return Integer.parseInt(next());
        }

        private static final void print(Object o) {
            out.print(o);
        }

        private static final void println(Object o) {
            out.println(o);
        }

        private static final void flush() throws Exception {
            out.flush();
        }

        @Override
        protected void finalize() throws Throwable {
            super.finalize();
            while(true) {
                Thread.yield();
            }
        }
    }
}